def ac_control(q):
  if q >= 30:
    print("Yes")
  else:
    print("No")
if __name__ == '__main__':
    q = int(input())
    ac_control(q) def ac_control(q):
  if q >= 30:
    print("Yes")
  else:
    print("No") ac_control if q >= 30:
    print("Yes")
  else:
    print("No") q >= 30 q 30 print("Yes") print "Yes" print("No") print "No" q q if __name__ == '__main__':
    q = int(input())
    ac_control(q) __name__ == '__main__' __name__ '__main__' q = int(input()) q int(input()) int input() input ac_control(q) ac_control q def ac_control(q):
  if q >= 30:
    print("Yes")
  else:
    print("No") def ac_control(q):
  if q >= 30:
    print("Yes")
  else:
    print("No") ac_control q = int(input()) int(input()) q
def ac_control(q):
  if q >= 30:
    print("Yes")
  else:
    print("No")
if __name__ == '__main__':
    q = int(input())
    ac_control(q)